Endoscopic treatment device, endoscopic treatment system, and endoscopic treatment method

ABSTRACT

A treatment device includes a pipeline having electrical insulation, the pipeline having an internal space through which inert gas passes; a distal-end tip attached to a distal end of the pipeline, the distal-end tip having an opening formed to communicate with the internal space such that the inert gas is disposable from the opening; and an electrode provided in the distal-end tip and configured to be energizable with a high-frequency current. The pipeline includes a proximal-end bending portion with a bending habit, and a distal-end flexible portion without a bending habit that is disposed distal to the proximal-end bending portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of International Application No. PCT/JP2020/048466, filed Dec. 24, 2020, which claims priority to International Application No. PCT/JP2020/000451, filed Jan. 9, 2020. The contents of the prior applications are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an endoscopic treatment device, and endoscopic treatment system, and an endoscopic treatment method.

BACKGROUND ART

As a treatment with respect to the gastroesophageal reflux disease (GERD), an oral treatment of a gastric acid secretion inhibitor and surgical operations such as laparoscopic Nissen fundoplication or the like are known. Oral treatment is not a radical cure, and it is necessary to continue taking the inhibitor for a long period of time, and there may be a case in which the symptoms does not improve. A surgical operation can effect a radical cure, however, it is more invasive. Since GERD is not a malignant disease such as a tumor or the like, it is desirable that the invasion associated with the treatment is as small as possible.

Various endoscopic treatments are being considered as options other than oral treatment and surgical treatment. As one of the endoscopic treatments, the mucosa near the gastroesophageal junction is resected such that a scar is generated at the resection site and the resection site is narrowed. As a result, the reflux of the gastric contents is suppressed.

SUMMARY

According to an aspect of the present disclosure, an endoscopic treatment device includes a pipeline having electrical insulation, the pipeline having an internal space through which inert gas passes; a distal-end tip attached to a distal end of the pipeline, the distal-end tip having an opening formed to communicate with the internal space such that the inert gas is disposable from the opening; and an electrode provided in the distal-end tip and configured to be energizable with a high-frequency current; wherein the pipeline has a bending portion formed to be stored to a predetermined bending shape, the bending portion includes a distal-end bending portion and a proximal-end bending portion, and a distal-end flexible portion without a bending habit is disposed between the proximal-end bending portion and the distal-end bending portion.

Another aspect of the present disclosure includes an endoscopic treatment method by an endoscope and a treatment device used in combination of the endoscope, wherein the treatment device comprises a pipeline having electrical insulation, the pipeline having an internal space through which inert gas passes; a distal-end tip attached to a distal end of the pipeline, the distal-end tip having an opening formed to communicate with the internal space such that the inert gas is disposable from the opening; and an electrode provided in the distal-end tip and configured to be energizable with a high-frequency current. The endoscopic treatment method includes inserting the treatment device through a channel of the endoscope; protruding a distal-end portion of the pipeline from a distal end of the channel and moving an opening of the distal-end tip from a protruding direction of the distal-end portion of the pipeline toward a direction different from the protruding direction; and in a state in which the opening of the distal-end tip is directed to the direction different from the protruding direction of the distal-end portion of the pipeline, injecting the inert gas into the internal space of the distal-end tip while energizing the electrode with the high-frequency current to cauterize a luminal wall of a hollow organ.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing an overall configuration of an endoscopic system including a treatment device according to an exemplary embodiment of the present disclosure.

FIG. 2 is a planar view of the treatment device.

FIG. 3 is a perspective view of a distal-end portion of the treatment device.

FIG. 4 is a cross-sectional view of the distal-end portion of the treatment device.

FIG. 5 is a cross-sectional view of an operation portion of the treatment device.

FIG. 6 is a view showing a state of observing a gastroesophageal junction by an endoscope inserted into the stomach.

FIG. 7 is a view showing the gastroesophageal junction around the cardia observed by the endoscope.

FIG. 8 is a view showing the endoscope for observing the gastroesophageal junction.

FIG. 9 is a view showing the endoscope approaching a specified treatment region.

FIG. 10 is a schematic cross-sectional view of the stomach wall.

FIG. 11 is a view showing the treatment device inserting through a treatment device channel.

FIG. 12 is a view showing the treatment device inserting through the bent treatment device channel.

FIG. 13 is a view showing a distal-end tip protruding from a distal end of the treatment device channel.

FIG. 14 is a view capturing a side opening of the treatment device whose position is determined.

FIG. 15 is a view showing the treatment device that is deployed at a position to cauterize the treatment region by a frontal approach.

FIG. 16 is a cross-sectional view showing the distal-end portion of the treatment device when cauterizing the treatment region.

FIG. 17 is a perspective view showing a modification example of the distal-end tip.

FIG. 18 is a perspective view showing the treatment device according to an exemplary embodiment of the present disclosure.

FIG. 19 is a perspective view showing a distal-end portion of the treatment device.

FIG. 20 is a view capturing a distal-end opening of the treatment device whose position is determined.

FIG. 21 is a perspective view of the treatment device including a modification example of the distal-end tip of the treatment device.

FIG. 22 is a perspective view showing the treatment device according to an exemplary embodiment of the present disclosure.

FIG. 23 is a front view showing a distal-end portion of the treatment device when viewed from the direction B in FIG. 22.

FIG. 24 is a view capturing the distal-end opening of the treatment device whose position is determined.

FIG. 25 is a planar view showing the treatment device according to an exemplary embodiment of the present disclosure.

FIG. 26 is a planar view showing the treatment device.

FIG. 27 is a cross-sectional view showing an operation portion of the treatment device.

FIG. 28 is a view showing a distal-end portion of a modification example of the treatment device.

DESCRIPTION OF EMBODIMENTS

An exemplary embodiment of the present disclosure will be described with reference to FIG. 1 to FIG. 16.

[Endoscopic Treatment System 300]

FIG. 1 is a view showing an overall configuration of an endoscopic treatment system 300 according to the present embodiment. The endoscope treatment system 300 includes an endoscope 200 and a treatment device 100 inserted into a channel of the endoscope 200.

[Endoscope 200]

The endoscope 200 is a well-known flexible endoscope, and includes an elongated insertion portion 210 and an operation portion 220 provided at a proximal-end portion of the insertion portion 210. The insertion portion 210 has a distal-end portion 201, a bending portion 204, and a flexible portion 205. The distal-end portion 201, the bending portion 204, and the flexible portion 205 are connected in this sequence from the distal end of the insertion portion 210. An imaging unit 216 having a light guide 215 and a CCD or the like is provided at the distal-end portion 201 of the insertion portion 210.

A treatment device channel 230 for inserting an endoscopic treatment device such as the treatment device 100 is formed in the insertion portion 210. The distal-end portion 230 a of the treatment device channel 230 is open at the distal-end portion 201 of the insertion portion 210. The proximal-end portion of the treatment device channel 230 extends to the operation portion 220.

The bending portion 204 is configured to be freely bent in the up-down vertical direction and the right-left horizontal direction. The distal end of the operation wire is fixed to the distal-end side of the bending portion 204. The operation wire extends through the insertion portion 210 to the operation portion 220.

On the proximal-end side of the operation portion 220, a knob 223 for operating the operation wire, a switch 224 for operating the imaging unit 216, and the like are provided. A user can bend the insertion portion 210 in a desired direction by operating the knob 223.

A forceps opening 222 communicating with the treatment device channel 230 is provided on the distal-end side of the operation portion 220. The user can insert an endoscopic treatment device such as the treatment device 100 from the forceps opening 222.

As shown in FIG. 1, the treatment device 100 can be attached to a treatment device driving apparatus 400 via a connector 401. The treatment device driving apparatus 400 includes, in a housing 410, a compressed gas source 411 filled with inert gas such as the argon gas or the like, a pressure regulator 412 configured to adjust the pressure of the inert gas supplied from the compressed gas source 411 so as to supply to the treatment device 100, a high-frequency power supply 413 configured to generate a high-frequency current supplied to the treatment device 100, and a controller 414 for controlling all the configurations in an integrated manner.

[Treatment Device 100]

FIG. 2 is a plan view showing the treatment device 100. FIG. 3 is a perspective view of the distal-end portion of the treatment device 100. FIG. 4 is a cross-sectional view of the distal-end portion of the treatment device 100. The treatment device 100 is formed in an elongated shape as a whole, and includes a gas pipeline 1, an electrode 3, and an operation portion 4.

As shown in FIG. 1, the gas pipeline (pipeline) 1 is a tubular member having an outer diameter that allows for the gas pipeline 1 to be inserted into the treatment device channel 230 of the endoscope 200. The tubular member is elongated and flexible. The internal space L1 of the gas pipeline 1 is a part of the gas flow path P1 through which the inert gas such as the argon gas flows. The gas pipeline 1 is made of a material having electrical insulation such as PTFE (Poly Tetra Fluoro Ethylene).

The gas pipeline 1 has a proximal-end portion 11 and a distal-end portion 12. The proximal-end portion 11 of the gas pipeline 1 is attached to the operation portion 4. Further, the gas pipeline 1 has a distal-end flexible portion 16, a proximal-end bending portion 17, and a proximal-end flexible portion 18 between the distal-end portion 12 and the proximal-end portion 11. The distal-end flexible portion 16, the proximal-end bending portion 17, and the proximal-end flexible portion 18 are sequentially connected in this order from the distal-end portion 12 toward the proximal-end portion 11.

As shown in FIG. 3, the gas pipeline 1 has a side opening 14 d at the distal-end portion 12. The side opening 14 d communicates with the internal space L1 of the gas pipeline 1 such that the inert gas is dischargeable therefrom. The internal space L1 of the gas pipeline 1 extends along the longitudinal axis from the side opening 14 d to the proximal end of the gas pipeline 1. The inert gas injected from the gas-supply port 42 a provided at the proximal end of the gas-supply line 42 flows through the internal space L1 of the gas pipeline 1 and is discharged from the side opening 14 d of the gas pipeline 1. In the following description, the direction in which the gas pipeline 1 extends is referred to as an axial direction A.

Specifically, a distal-end tip 14 is attached to the distal-end portion 12 of the gas pipeline 1. As shown in FIG. 3, the distal-end tip 14 has a disc-shaped disc frame 14 a and a cylindrical frame 14 b in a cylindrical shape. The disk frame 14 a is provided on the distal-end side of the distal-end tip 14, and closes the opening on the front side of the cylindrical frame 14 b. The opening on the rear side of the cylindrical frame 14 b communicates with the internal space L1 of the gas pipeline 1. A side opening 14 d is formed on the lateral side of the cylindrical frame 14 b.

The distal-end flexible portion 16 is a pipeline that does not have a bending habit, and the distal-end portion 12 is attached to the distal end of the distal-end flexible portion 16.

The proximal-end bending portion 17 is a pipeline having a bending habit, and is restored to a predetermined bending shape in a state where there is no external force applied. The bending habit (pre-curve) is, for example, a shape formed by the thermoforming processing or the like such that a resin tube is restored to a bending shape. In other words, “bending habit” as used herein refers to the tendency to return to a predetermined bent (curved) shape when no external force is applied. The shape of the proximal-end bending portion 17 shown in FIG. 2 is the predetermined bending shape in a state in which there is no external force applied. The predetermined bending shape of the proximal-end bending portion 17 in a state where there is no external force applied is also referred to as an “initial bending shape”. The initial bending shape of the proximal-end bending portion 17 is bent in one direction. The initial bending shape of the proximal-end bending portion 17 is bent along a virtual plane V.

The proximal-end flexible portion 18 is a pipeline that does not have a bending habit, and is attached to the operation portion 4 via the proximal-end portion 11.

As shown in FIG. 2, when the proximal-end bending portion 17 is in the initial bending shape while the distal-end flexible portion 16 and the proximal-end flexible portion 18 are in a linear state, the lateral opening of the distal-end tip 14 provided in the distal-end portion 12 14 d is open in a direction perpendicular to the virtual plane V.

In the gas pipeline 1, it is desirable that the length L7 of the proximal-end bending portion 17 in the axial direction is longer than the length L6 of the distal-end flexible portion 16 in the axial direction.

The electrode 3 is a wire-shaped member and is arranged in the internal space L1 of the gas pipeline 1. The electrode 3 is made of a metal material, has conductivity, and is energizable by a high-frequency current. The most proximal end of the proximal-end portion 31 of the electrode 3 is connected to a high frequency power supply 413 that supplies the high-frequency current.

The material of the electrode 3 is preferably a material having flexibility and elasticity so as to easily restore to the linear state even if the electrode 3 is bent by the external force. For example, as the material of the electrode 3, an alloy material such as a stainless alloy, a nickel-titanium alloy, a cobalt-chromium alloy, a tungsten, a tungsten alloy or the like can be adopted.

As shown in FIG. 3, the distal-end portion 32 of the electrode 3 is arranged at a position so as to be seen from the side opening 14 d in a side view viewed from a direction perpendicular to the axial direction A. As shown in FIG. 4, it is preferable that the central axis O2 of the electrode 3 substantially coincides with the central axis O1 of the gas pipeline 1.

FIG. 5 is a cross-sectional view of the operation portion 4.

The operation portion 4 has an operation portion main body 40 to which the proximal-end portion 11 of the gas pipeline 1 is connected, and a gas-supply pipeline 42.

The distal-end portion of the operation portion main body 40 is fixed to the proximal-end portion 11 of the gas pipeline 1. The proximal-end portion of the operation portion main body 40 is fixed to the gas-supply pipeline 42. The gas pipeline 1 and the gas-supply pipeline 42 are connected with each other, and the internal space L1 of the gas pipeline 1 communicates with the internal space L4 of the gas-supply pipeline 42.

The gas-supply pipeline 42 is a pipeline for supplying inert gas such as the argon gas to the internal space L1 of the gas pipeline 1. The gas-supply port 42 a provided at the distal end of the gas-supply pipeline 42 can be connected to the pressure regulator 412 by being attached to the treatment device driving apparatus 400 via the connector 401.

The electrode 3 penetrates the operation portion main body 40. The proximal-end portion 31 of the electrode 3 passes through the internal space L4 of the gas-supply pipeline 42 and extends to the outside of the operation portion 4. As shown in FIG. 1, the most proximal end of the proximal-end portion 31 of the electrode 3 together with the proximal end of the gas-supply pipeline 42 are attached to the treatment device driving apparatus 400 via the connector 401 so as to connect with the high frequency power supply 413. The most proximal end of the proximal end portion 31 of the electrode 3 does not necessarily have to extend to the high frequency power supply 413. For example, the most proximal end of the proximal end portion 31 of the electrode 3 may be located in the operation portion 4. In this case, a configuration for connecting with the high frequency power supply 413 by another metal wire via a plug or the like electrically connected to the most proximal end of the proximal end portion 31 of the electrode 3 may be adopted.

[Effect of Endoscopic Treatment System 300]

Next, the effects of the endoscopic treatment system 300 according to the present embodiment will be described. The effects of the endoscopic treatment system 300 will be described by taking an endoscopic treatment method for the gastroesophageal reflux disease (GERD) using the endoscopic treatment system 300 as an example. The endoscopic treatment method to which the endoscopic treatment system 300 is applied is not limited to this example. For example, the endoscopic treatment system 300 is also applied to an endoscopic treatment method for resecting a part of a lesion or the like.

The surgeon inserts the endoscope 200 through a natural orifice such as the mouth or the nose of the target (insertion step), and moves the distal-end portion 201 of the endoscope 200 into the stomach (gastrointestinal tract).

FIG. 6 is a view showing a state of observing the gastroesophageal junction by the endoscope 200 inserted into the stomach.

The surgeon then bends the endoscope 200. As shown in FIG. 6, the surgeon directs the distal-end portion 201 of the endoscope 200 toward the cardia Co, and captures the gastroesophageal junction around the cardia Co within the view field of the endoscope 200. While observing the gastroesophageal junction, the surgeon identifies a treatment region R, which is the target of the local injection treatment or cauterization treatment described later (treatment region identification step).

FIG. 7 is a view showing the gastroesophageal junction around the cardia Co that is observed by the endoscope 200.

The treatment region R in the endoscopic treatment method for GERD is, for example, a first region R11 and a second region area R12 in a C-shape or U-shape. The first region R11 and the second region R12 have a shape facing each other to sandwich the cardia Co therebetween. The first region R11 is located on the anterior wall side of the stomach. The second region R12 is located on the posterior wall side of the stomach. The first region R11 and the second region R12 extend in the circumferential direction C of the gastroesophageal junction. For example, among the treatment regions R (first region R11 and second region R12), the greater curvature side is regarded as a treatment region R1 and the lesser curvature side is regarded as a treatment region R2.

FIG. 8 is a view showing the endoscope 200 for observing a gastroesophageal junction.

In a case in which the distal-end portion 201 of the endoscope 200 is directed toward the cardia Co to observe or perform treatment with respect to the gastroesophageal junction around the cardia Co in the stomach, it is desirable that the bending portion 204 of the endoscope 200 is greatly bent and inverted. Therefore, the surgeon puts the bending portion 204 of the endoscope 200 in a state of being bent in a direction (upper direction) such that the bending portion 204 can be bent with the largest curvature amount (so-called the up-angle state). As shown in FIG. 8, the surgeon sets the bending portion 204 in the up-angle state and rotates the flexible portion 205 around the longitudinal axis such that the position of the distal-end portion 201 of the endoscope 200 can be moved to be between the vicinity of the treatment region R1 and the vicinity of the treatment region R2.

FIG. 9 is a view showing the treatment device 100 approaching the specified treatment region R.

Methods of approaching the treatment region R include at least a frontal approach AP1 and a tangential approach AP2. In the frontal approach AP1, the surgeon arranges the treatment device 100 at a position where the distal-end portion 12 of the gas pipeline 1 faces the treatment region R by operating the treatment device 100 or the distal-end portion 201 of the endoscope 200. In the tangential approach AP2, the treatment device 100 is arranged at a position where the side portion of the distal-end portion 12 of the gas pipeline 1 faces the treatment region R.

Next, the surgeon bulges the treatment region R by performing the local injection of a liquid into the submucosal layer N of the specified treatment region R (local injection step). The liquid to be injected is physiological saline, sodium hyaluronate solution, glycerin or the like. The surgeon passes a treatment device such as a local injection needle through the treatment device channel 230 of the endoscope 200. The surgeon injects the physiological saline solution or the like into the treatment region R to bulge the treatment region R. If it is not necessary to bulge the treatment region R, the local injection step can be omitted.

The surgeon may use a treatment device such as a high frequency knife, a heat probe or the like to forma marking around the treatment region R before performing the local injection step (marking step). The marking is performed by locally cauterizing the mucosa at the periphery of the treatment region R.

Next, the surgeon cauterizes the bulged treatment region R. At this time, only the cauterization is performed without resecting the mucous membrane. The degree of the cauterization is such that the mucosal basal layer M is damaged. FIG. 10 shows a schematic cross-sectional view of the stomach wall. The mucosal basal layer M is a part of the mucosal layer L and the mucosal basal layer M is a layer including a boundary surface in contact with the submucosal layer N. The mucosal basal layer M may also be referred to as a basement membrane.

FIG. 11 is a view showing a treatment device 100 inserted through the treatment device channel 230.

The surgeon passes the treatment device 100 through the treatment device channel 230 of the endoscope 200 (insertion step). Next, the surgeon protrudes the side opening 14 d of the distal-end tip 14 from the distal-end portion 230 a of the treatment device channel 230 (protrusion step). A direction in which a distal region of the gas pipeline 1, including the distal-end tip 14, protrudes from the distal-end portion 230 a is defined as a “protruding direction D” (see FIG. 13).

As shown in FIG. 11, when the bending portion 204 of the endoscope 200 is not bent, the treatment device channel 230 is also not bent. The proximal-end bending portion 17 of the gas pipeline 1 of the treatment device 100 inserted into the treatment device channel 230 that is not bent meanders in the treatment device channel 230.

FIG. 12 is a view showing the treatment device 100 inserted through the bent treatment device channel 230. The surgeon puts the bending portion 204 in the up-angle state (bending step). When the bending portion 204 of the endoscope 200 is bent, the treatment device channel 230 is also bent. In a case in which when the proximal-end bending portion 17 is located in the bent treatment device channel 230, and the bending direction of the bending shape of the proximal-end bending portion 17 located in the treatment device channel 230 is different from the bending direction of the initial bending shape of the proximal-end bending portion 17, the proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1 until the bending shape of the proximal-end bending portion 17 almost follows the bending shape of the treatment device channel 230.

When the proximal-end bending portion 17 is located in the treatment device channel 230 that is bent by the bending portion 204, there are many cases that the bending direction of the bending shape of the treatment device channel 230 and the bending direction of the initial bending shape of the proximal-end bending portion 17 are different. Therefore, it is easy for the passive rotation operation of the proximal-end bending portion 17 as described above to occur.

FIG. 13 is a view showing the distal-end tip 14 protruding from the distal end of the treatment device channel 230.

When the proximal-end bending portion 17 as described above passively rotates around the central axis of the gas pipeline 1, the side opening 14 d moves with respect to the distal-end portion 201 of the endoscope 200.

As shown in FIG. 13, when the proximal-end bending portion 17 passes through the treatment device channel 230 bent by the bending portion 204, the gas pipeline 1 is bent along the virtual plane V. At that time, the side opening 14 d is positioned so as to face the direction perpendicular to the virtual plane V. At that time, the side opening 14 d faces a direction different from the protruding direction D of the distal-end tip 14. The proximal-end bending portion 17 does not necessarily have to be restored to the initial bending shape, and even if in a case in which the proximal-end bending portion 17 does not restore to the initial bending shape, the proximal-end bending portion 17 follows the bending shape of the treatment device channel that is bent by the bending portion 204 until it follows the bending shape, The proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1.

In a case in which the bending direction of the bending shape of the treatment device channel 230 and the bending direction of the bending shape of the proximal-end bending portion 17 located in the treatment device channel 230 coincide with each other, the side opening 14 d has already been positioned to be in the state of facing the direction perpendicular to the virtual plane V.

FIG. 14 is an image showing the positioned side opening 14 d.

From the positional relationship between the imaging unit 216 of the endoscope 200 and the distal-end portion 230 a of the treatment device channel 230, the distal-end tip 14 protruding from the distal end of the treatment device channel 230 is located at the lower left in the image captured by the endoscope 200. The side opening 14 d whose position is determined faces to the right in the captured image. Therefore, the surgeon does not have to deploy the distal-end tip 14B directly above the treatment region R.

FIG. 15 is a view showing the treatment device 100 arranged at the position where the treatment region R1 is cauterized by the frontal approach AP1. In the frontal approach AP1, the surgeon arranges the treatment device 100 at a position where the distal-end portion 12 of the gas pipeline 1 faces the treatment region R1 by operating the treatment device 100 or the endoscope 200.

The surgeon supplies the inert gas to the gas supply port 42 a. The supplied inert gas is discharged from the side opening 14 d of the distal-end portion 12 of the gas pipeline 1 to the vicinity of the treatment region R1 via the gas flow path P1. The surgeon supplies the inert gas while supplying the high-frequency current to the electrode 3. By discharging the high-frequency current in the inert gas, the inert gas is ionized and becomes plasma. Since the plasma has electrical conductivity, the plasma is used as a medium to promote stable maintenance of the discharge from the distal-end portion 32 of the electrode 3 toward the treatment region R1. As a result, the treatment region R1 is cauterized (cauterization step) in a state where the distal-end portion 32 of the electrode 3 and the treatment region R1 are not in contact with each other.

In the frontal approach AP1, the surgeon changes the cauterization position in a direction E (see FIG. 7) extending from the inside of the stomach toward the cardia Co by the operation OP1 for bending the bending portion 204 of the endoscope 200. Also, the surgeon changes the cauterization position in the circumferential direction C (see FIG. 7) of the gastroesophageal junction by the operation OP2 of twisting the flexible portion 205 of the endoscope 200. The surgeon cauterizes the entire treatment region R1 while changing the cauterization position.

FIG. 16 is a view showing the treatment device 100 arranged at a position where the treatment region R2 is cauterized by the tangential approach AP2. In the tangential approach AP2, the surgeon arranges the treatment device 100 at a position where the side portion of the distal-end portion 12 of the gas pipeline 1 faces the treatment region R2 by operating the treatment device 100 or the endoscope 200.

Also in the tangential approach AP2, the surgeon supplies the inert gas to the gas supply port 42 a. The supplied inert gas is discharged from the side opening 14 d of the distal-end portion 12 of the gas pipeline 1 to the vicinity of the treatment region R2 via the gas flow path P1. The surgeon supplies an inert gas while supplying the high-frequency current to the electrode 3. By discharging the high-frequency current in the inert gas, the inert gas is ionized and becomes plasma. Since the plasma has electrical conductivity, the plasma is used as the medium to promote stable maintenance of the discharge from the distal-end portion 32 of the electrode 3 toward the treatment region R2. As a result, the treatment region R2 is cauterized (cauterization step) in a state where the distal-end portion 32 of the electrode 3 and the treatment region R2 are not in contact with each other.

In the tangential approach AP2, the surgeon changes the cauterization position in the direction E (see FIG. 7) from the inside of the stomach toward the cardia Co by the advance-retreat operation OP3 of the treatment device 100. Also, the surgeon changes the cauterization position in the circumferential direction C (see FIG. 7) of the gastroesophageal junction by the operation OP4 of twisting the flexible portion 205 of the endoscope 200. The surgeon cauterizes the entire treatment region R2 while changing the cauterization position.

The side opening 14 d is positioned at a position facing the right side in the captured image. In particular, in the tangential approach AP2, the distal-end tip 14 can be arranged at a position where the treatment region R can be cauterized while visually recognizing the treatment region R in the captured image. The surgeon does not have to alternate between the cauterization operation and the visually confirmation operation.

The sequence of the frontal approach AP1 and the tangential approach AP2 may be exchanged, and the cauterization in the frontal approach AP1 may be performed after the cauterization in the tangential approach AP2.

According to the treatment device 100 of the present embodiment, since the range that can be cauterized at once is wider than that of the treatment device such as a high-frequency knife, it is possible to quickly cauterize a wide treatment range R. When cauterizing the treatment region R, the distal-end portion 32 of the electrode 3 is arranged in the distal-end tip 14. Therefore, it is difficult to accidentally cause scorching due to the contact between the distal-end portion 32 of the electrode 3 and the tissues during the cauterization.

Since the mucosal basal layer M is damaged by cauterization, the gastric mucosa of the treatment region R is subsequently regenerated through the process of the scar formation. At the time of the mucosal regeneration, the gastric mucosa surrounding the treatment region R is attracted toward the treatment region R by the contractile action of the tissue surrounding the treatment region R in the process of the scar formation when the damaged mucosa heals. Utilizing this effect, the symptom of GERD is improved by forming an incomplete stenosis in the cardia Co to prevent the reflux symptom.

At a case of generating the incomplete stenosis in the cardia Co, the surface area of the mucosal surface in the treatment region R where the cauterization is required is large. Since the treatment device 100 configured to perform the cauterization using the inert gas and the high-frequency current has a wider range which can be cauterized at once than that of a treatment device such as the high-frequency knife, it is possible to perform the cauterization quickly over a wide treatment range R, simplify the treatment and shorten the time necessary for the treatment.

In a case of cauterizing the gastroesophageal junction around the cardia Co, as shown in FIG. 9, it is necessary to significantly bend the distal-end portion 201 of the endoscope 200. Since the treatment device 100 has a side opening 14 d on the lateral side, it is possible to cauterize the treatment region R located on the lateral side by discharging the inert gas from the side opening 14 d and discharging the high-frequency current in the inert gas.

Although the present embodiment of the present disclosure has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a range that does not deviate from the scope of the present invention. In addition, the components shown in the above-described embodiment and the modification examples shown below can be appropriately combined and configured.

For example, in the above embodiment, the positional relationship between the imaging unit 216 of the endoscope 200 and the distal-end portion 230 a of the treatment device channel 230 is an example. The position of the side opening 14 d provided on the distal-end tip 14 is appropriately changed according to the configuration of the distal-end portion of the used endoscope.

For example, in the above described embodiment, the distal-end tip 14 has the side opening 14 d as an opening. However, the embodiment of the opening provided in the distal-end tip 14 is not limited to this example. FIG. 17 is a perspective view of the distal-end tip 14A as a modification example of the distal-end tip 14. The distal-end tip 14A has a distal-end opening 14 c and the side opening 14 d. The distal-end tip 14A has an annular ring frame 14Ba in an annular ring shape and a cylindrical frame 14 b in a cylindrical shape. The annular ring frame 14Ba is provided in the opening on the front end side of the distal-end tip 14A and on the front end side of the cylindrical frame 14 b. The annular ring frame 14Ba has a distal-end opening 14 c. The distal-end opening 14 c is open in the axial direction A. The distal-end opening 14 c communicates with the internal space L1 of the gas pipeline 1 where the inert gas can be discharged. If the distal-end tip 14A having the distal-end opening 14 c is used, the treatment region R arranged in the front of the distal-end tip 14A can be easily cauterized in the frontal approach AP1.

Another exemplary embodiment of the present disclosure will be described with reference to FIG. 18 to FIG. 20. In the following description, the same reference signs will be given to the configurations common to those already described, and duplicate description will be omitted. The treatment device 100B according to the present embodiment has a configuration of the gas pipeline different from that of the treatment device 100 according to the above embodiment of FIG. 1 to FIG. 16.

[Treatment Device 100B]

FIG. 18 is a perspective view of the treatment device 100B. FIG. 19 is a perspective view of the distal-end portion of the treatment device 100B. The treatment device 100B is formed in an elongated shape as a whole, and the treatment device 100B includes a gas pipeline 1B, an electrode 3, and an operation portion 4.

The gas pipeline (pipeline) 1B is a tubular member having an outer diameter that allows for the gas pipeline 1 to be inserted into the treatment device channel 230 of the endoscope 200. The tubular member is elongated and flexible. The internal space L1 of the gas pipeline 1B is a part of the gas flow path P1 through which the inert gas such as the argon gas or the like flows. The gas pipeline 1B is made of a material having electrical insulation such as the PTFE.

The gas pipeline 1B has a proximal-end portion 11 and a distal-end portion 12B. The proximal-end portion 11 of the gas pipeline 1B is attached to the operation portion 4. Further, the gas pipeline 1B has a distal-end bending portion 15, a distal-end flexible portion 16, a proximal-end bending portion 17, and a proximal-end flexible portion 18 between the distal-end portion 12B and the proximal-end portion 11. The distal-end bending portion 15, the distal-end flexible portion 16, the proximal-end bending portion 17, and the proximal-end flexible portion 18 are connected in this sequence from the distal-end portion 12B toward the proximal-end portion 11.

As shown in FIG. 19, the gas pipeline 1B has a distal-end opening 14 c at the distal-end portion 12. The distal-end opening 14 c communicates with the internal space L1 of the gas pipeline 1B where the inert gas can be discharged. The internal space L1 of the gas pipeline 1B extends along the longitudinal axis from the distal-end opening 14 c to the proximal end of the gas pipeline 1B. The inert gas injected from the gas supply port 42 a provided at the proximal end of the gas-supply pipeline 42 flows through the internal space L1 of the gas pipeline 1B and is discharged from the distal-end opening 14 c of the gas pipeline 1B. In the following description, the direction in which the gas pipeline 1B extends is referred to as the axial direction A.

Specifically, the distal-end tip 14B is attached to the distal-end portion 12B of the gas pipeline 1B. The distal-end tip 14B has an annular ring frame 14Ba in an annular ring shape and a cylindrical frame 14Bb in a cylindrical shape. The annular ring frame 14Ba is provided in the opening on the front side of the distal-end tip 14B and on the front side of the cylindrical frame 14Bb. The annular ring frame 14Ba has a distal-end opening 14 c. The distal-end opening 14 c is open in the axial direction A. The rear opening of the cylindrical frame 14Bb communicates with the internal space L1 of the gas pipeline 1B.

The distal-end bending portion 15 is a pipeline having a bending habit, and is restored to a predetermined bending shape in a state where there is no external force applied. The bending habit (pre-curve) is, for example, a shape formed by the thermoforming processing or the like such that a resin tube is restored to a bending shape. The shape of the distal-end bending portion 15 as shown in FIG. 18 is the predetermined bending shape in a state in which there is no external force applied. The predetermined bending shape of the distal-end bending portion 15 in a state where there is no external force applied is also referred to as an “initial bending shape”. The initial bending shape of the distal-end bending portion 15 is bent in a direction intersecting with the virtual plane V. According to the present embodiment, the initial bending shape of the distal-end bending portion 15 is bent along the direction perpendicular to the virtual plane V.

The distal-end bending portion 15 has a distal-end tip 14B at the distal end thereof. As shown in FIG. 18, in a case in which the distal-end bending portion 15 and the proximal-end bending portion 17 are in the initial bending shape and the distal-end flexible portion 16 and the proximal-end flexible portion 18 are in a linear state, the distal-end opening 14 c of the distal-end tip 14B provided in the distal-end portion 12B opens in the direction perpendicular to the virtual plane V.

In the gas pipeline 1B, it is desirable that the length L7 in the axial direction A of the proximal-end bending portion 17 is longer than the length L6 of the distal-end flexible portion 16 in the axial direction thereof. Also, the length L7 in the axial direction A of the proximal-end bending portion 17 is longer than the length L5 in the axial direction A of the distal-end bending portion 15.

The curvature of the distal-end bending portion 15 is larger than the curvature of the proximal-end bending portion 17. Also, the radius of curvature of the distal-end bending portion 15 is equal to or less than half of the axial length L6 of the distal-end flexible portion 16 in the axial direction thereof.

Next, the effects of the treatment device 100B of the present embodiment will be described. The treatment device 100B, similar to the treatment device 100, can be used in combination with the endoscope 200 for the endoscopic treatment method for the gastroesophageal reflux disease (GERD).

Similar to the above embodiment of FIG. 1 to FIG. 16, the surgeon specifies the treatment region R (treatment area identification step). The surgeon makes the bending portion 204 to be in the up-angle state to observe and treat the gastroesophageal junction. The surgeon bulges the treatment region R by locally injecting the liquid into the submucosal layer N of the identified treatment region R (local injection step).

Next, similar to the above embodiment of FIG. 1 to FIG. 16, the surgeon cauterizes the bulged treatment region R. The surgeon inserts the treatment device 100B through the treatment device channel 230 of the endoscope 200 (insertion step). Next, the surgeon protrudes the distal-end opening 14 c of the distal-end tip 14 and the distal-end bending portion 15 from the distal-end portion 230 a of the treatment device channel 230 (protruding step).

When the proximal-end bending portion 17 passes through the treatment device channel 230 bent by the bending portion 204, the proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1B until the bending shape of the proximal-end bending portion 17 almost follows the bending shape of the treatment device channel 230.

When the proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1B, the distal-end opening 14 c moves with respect to the distal-end portion 201 of the endoscope 200.

When the proximal-end bending portion 17 passes through the treatment device channel 230 bent by the bending portion 204, similar to the above embodiment of FIG. 1 to FIG. 16, the gas pipeline 1B is bent along the virtual plane V. At that time, as shown in FIG. 18, the distal-end opening 14 c is positioned so as to face the direction perpendicular to the virtual plane V. At that time, the distal-end opening 14 c faces a direction different from the protruding direction D of the distal region of the gas pipeline 1B including the distal-end tip 14B. The proximal-end bending portion 17 does not necessarily have to be restored to the initial bending shape, and even if in the case in which the proximal-end bending portion 17 is not restored to the initial bending shape, the proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1B until the bending shape of the proximal-end bending portion 17 follows the bending shape of the treatment device channel bent by the bending portion 204.

FIG. 20 is a view capturing the distal-end opening 14 c whose position is determined. When the surgeon protrudes the distal-end bending portion 15 from the distal-end portion 230 a of the treatment device channel 230, the distal-end bending portion 15 is bent to the initial bending shape due to the bending habit. Due to the positional relationship between the imaging unit 216 of the endoscope 200 and the distal-end portion 230 a of the treatment device channel 230, the distal-end tip 14B protruding from the distal end of the treatment device channel 230 is located at the lower left in the image captured by the endoscope 200. The positioned distal-end opening 14 c faces to the right in the captured image. Accordingly, since the surgeon does not have to deploy the distal-end tip 14B directly above the treatment region R, it is easy to visually confirm the cauterization state of the treatment region R in the captured image when the treatment region R is cauterized.

The position of the distal-end opening 14 c is determined at a position facing the right side in the captured image. In particular, in the tangential approach AP2, the distal-end tip 14B can be arranged at a position so as to be able to cauterize the treatment region R while the treatment region R can be visually confirmed in the captured image. Therefore, the surgeon can perform the cauterization operation while performing the visual confirmation operation to confirm the cauterization state in the captured image. The surgeon does not have to alternate between the visual confirmation operation and the cauterization operation.

According to the treatment device 100B of the present embodiment, since the range that can be cauterized at once is wider than that of the treatment device such as a high-frequency knife, it is possible to quickly cauterize a wide treatment range R. When cauterizing the treatment region R, the distal-end portion 32 of the electrode 3 is arranged in the distal-end tip 14. Therefore, it is difficult to accidentally cause scorching due to the contact between the distal-end portion 32 of the electrode 3 and the tissues during the cauterization.

Since the mucosal basal layer M is damaged by cauterization, the gastric mucosa of the treatment region R is subsequently regenerated through the process of the scar formation. At the time of the mucosal regeneration, the gastric mucosa surrounding the treatment region R is attracted toward the treatment region R by the contractile action of the tissue surrounding the treatment region R in the process of the scar formation when the damaged mucosa heals. Utilizing this effect, the symptom of GERD is improved by forming an incomplete stenosis in the cardia Co to prevent the reflux symptom.

Although the present embodiment of the present disclosure has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a range that does not deviate from the scope of the present invention. In addition, the components shown in the above-described embodiments and the modification examples shown below can be appropriately combined and configured.

For example, in the above described embodiment, the distal-end tip 14B has the distal-end opening 14 c as an opening. However, the embodiment of the opening provided in the distal-end tip 14B is not limited to this example. FIG. 21 is a perspective view of a treatment device 100BA provided with a distal-end tip 14A as a modification example of the distal-end tip 14. The distal-end tip 14A (see FIG. 17) has the distal-end opening 14 c and a side opening 14 d. When the position of the distal-end opening 14 c is determined, the side opening 14 d is arranged at a position facing the protruding direction D. If the distal-end tip 14A having the distal-end opening 14 c and the side opening 14 d is used, it is easy to cauterize the treatment region R arranged in front of the distal-end tip 14A in the frontal approach AP1.

Another exemplary embodiment of the present disclosure will be described with reference to FIG. 22 to FIG. 24. In the following description, the same reference signs will be given to the configurations common to those already described, and duplicate description will be omitted. The treatment device 100C according to the present embodiment has a different gas pipeline configuration as compared with that of the treatment device 100 according to the above embodiment of FIG. 1 to FIG. 16.

[Treatment Device 100C]

FIG. 22 is a perspective view of the treatment device 100C. FIG. 23 is a front view of the distal-end portion of the treatment device 100C as viewed from the direction B in FIG. 22. The treatment device 100C is formed in an elongated shape as a whole, and includes a gas pipeline 1C, the electrode 3, and the operation portion 4.

The gas pipeline (pipeline) 1C is a tubular member having an outer diameter that allows for the gas pipeline 1C to be inserted into the treatment device channel 230 of the endoscope 200. The tubular member is elongated and flexible. The internal space L1 of the gas pipeline 1C is a part of the gas flow path P1 through which the inert gas such as the argon gas flows. The gas pipeline 1C is made of a material having electrical insulation such as the PTFE.

The gas pipeline 1C has a proximal-end portion 11 and a distal-end portion 12C. The proximal-end portion 11 of the gas pipeline 1C is attached to the operation portion 4. Also, the gas pipeline 1C has a distal-end bending portion 15C, a distal-end flexible portion 16, a proximal-end bending portion 17, and a proximal-end flexible portion 18 between the distal-end portion 12C and the proximal-end portion 11. The distal-end bending portion 15C, the distal-end flexible portion 16, the proximal-end bending portion 17, and the proximal-end flexible portion 18 are connected in this sequence from the distal-end portion 12C toward the proximal-end portion 11.

As shown in FIG. 23, the gas pipeline 1C has a distal-end opening 14 c at the distal-end portion 12C. Specifically, a distal-end tip 14B (see FIG. 19) is attached to the distal-end portion 12B of the gas pipeline 1C. The distal-end opening 14 c communicates with the internal space L1 of the gas pipeline 1C so as to be able to discharge the inert gas. The internal space L1 of the gas pipeline 10 extends along the longitudinal axis from the distal-end opening 14 c to the proximal end of the gas pipeline 1C. The inert gas injected from the gas supply port 42 a provided at the proximal end of the gas-supply pipeline 42 flows through the internal space L1 of the gas pipeline 1C and is discharged from the distal-end opening 14 c of the gas pipeline 1C. In the following description, the direction in which the gas pipeline 1C extends is referred to as the axial direction A.

The distal-end bending portion 15C is a pipeline with a bending habit, and is restored to a predetermined curved shape. The bending habit (pre-curve) is, for example, a shape formed by the thermoforming processing or the like such that a resin tube is restored to a bending shape. The shape of the distal-end bending portion 15 as shown in FIG. 22 is a predetermined bending shape in a state where there is no external force applied. The predetermined curved shape of the distal-end bending portion 15C in the state where there is no external force applied is also referred to as an “initial bending shape”. As shown in FIG. 23, the initial bending shape of the distal-end bending portion 15C is bent in a C shape along a second virtual plane V2. The second virtual plane V2 is a plane obtained by rotating the virtual plane V with the central axis C of the distal-end flexible portion 16 in a linear state as the rotation center, and the rotation angle θ is equal to or more than zero degree and equal to or less than 90 degrees. In the present embodiment, the initial bending shape of the distal-end bending portion 15 has the rotation angle θ being approximately 30 degrees. In a case in which the rotation angle θ is zero degree, the virtual plane V and the second virtual plane V2 coincide with each other.

The distal-end bending portion 15C has the distal-end tip 14B at the distal end thereof. As shown in FIG. 23, when the distal-end bending portion 15C and the proximal-end bending portion 17 are in the initial bending shape and the distal-end flexible portion 16 and the proximal-end flexible portion 18 are in the linear state, the distal-end opening 14 c of the distal-end tip 14B provided on the distal-end portion 12C is located on the virtual plane V.

In the gas pipeline 1C, it is desirable that the length L7 in the axial direction A of the proximal-end bending portion 17 is longer than the length L6 of the distal-end flexible portion 16 in the axial direction thereof. Also, the length L7 in the axial direction A of the proximal-end bending portion 17 is longer than the length L5 in the axial direction A of the distal-end bending portion 15.

The curvature of the distal-end bending portion 15C is larger than the curvature of the proximal-end bending portion 17. Also, the curvature radius of the distal-end bending portion 15C is equal to or less than half of the length L3 of the distal-end flexible portion 16 and the distal-end bending portion 15C in the longitudinal axis direction.

Next, the effects of the treatment device 100C of the present embodiment will be described. The treatment device 100C, similar to the treatment device 100 according to the embodiment of FIG. 1 to FIG. 16, can be used in combination with the endoscope 200 for an endoscopic treatment method for the gastroesophageal reflux disease (GERD).

Similar to the embodiment of FIG. 1 to FIG. 16, the surgeon specifies the treatment region R (treatment area identification step). The surgeon makes the bending portion 204 in the up-angle state to observe and treat the gastroesophageal junction. The surgeon bulges the treatment region R by locally injecting the liquid into the submucosal layer N of the identified treatment region R (local injection step).

Next, similar to the embodiment of FIG. 1 to FIG. 16, the surgeon cauterizes the bulged treatment region R. The surgeon passes the treatment device 100C through the treatment device channel 230 of the endoscope 200 (insertion step). Next, the surgeon protrudes the distal-end opening 14 c of the distal-end tip 14 and the distal-end bending portion 15C from the distal-end portion 230 a of the treatment device channel 230 (protruding step).

When the proximal-end bending portion 17 passes through the treatment device channel 230 bent by the bending portion 204, the proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1C until the bending shape of the proximal-end bending portion 17 almost follows the bending shape of the treatment device channel 230.

When the proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1C, the distal-end opening 14 c moves with respect to the distal-end portion 201 of the endoscope 200.

In a case in which the proximal-end bending portion 17 is restored to the initial bending shape, similar to the embodiment of FIG. 1 to FIG. 16, the gas pipeline 1C is bent along the virtual plane V and the position of the distal-end opening 14 c is determined in a state in which the distal-end opening 14 c faces a direction along the second virtual plane. At this time, the distal-end opening 14 c faces a direction different from the protruding direction D of the distal region of the gas pipeline 1B including the distal-end tip 14B. The proximal-end bending portion 17 does not necessarily have to be restored to the initial bending shape, and even if in a case in which the proximal-end bending portion 17 is not restored to the initial bending shape, the proximal-end bending portion 17 passively rotates around the central axis of the gas pipeline 1C until the proximal-end bending portion 17 follows the bending shape of the treatment device channel that is bent by the bending portion 204.

FIG. 24 is a view capturing the distal-end opening 14 c whose position is determined.

When the surgeon protrudes the distal-end bending portion 15C from the distal-end portion 230 a of the treatment device channel 230, the distal-end bending portion 15C is bent to the initial bending shape due to the bending habit. From the positional relationship between the imaging unit 216 of the endoscope 200 and the distal-end portion 230 a of the treatment device channel 230, the distal-end tip 14B protruding from the distal end of the treatment device channel 230 is located at the lower left in the image captured by the endoscope 200. The distal-end opening 14 c whose position is determined faces the lower right side in the captured image. Therefore, the surgeon does not have to deploy the distal-end tip 14B directly above the treatment region R.

The position of the distal-end opening 14 c is determined in the state in which the distal-end opening 14 c faces the right side in the captured image. In particular, in the tangential approach AP2, the distal-end tip 145 can be arranged at a position where the treatment region R can be cauterized while the treatment region R can be visually confirmed in the captured image. Therefore, the surgeon can perform the cauterization operation while performing the visual confirmation operation of confirming the state of the cauterization on the captured image. The surgeon does not have to alternate between the visual confirmation operation and the cauterization operation.

Although the present embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a range that does not deviate from the scope of the present disclosure. Also, the components shown in the above-described embodiments and modification examples can be appropriately combined and configured.

For example, in the above described embodiment, the distal-end tip 14B has a distal-end opening 14 c as an opening. However, the embodiment of the opening provided in the distal-end tip 14B is not limited to this example. Similar to the modification example 2-1, the distal-end tip 14B may further have an opening that is arranged at a position facing the protrusion direction D when the position of the distal-end opening 14 c is determined.

Another exemplary embodiment of the present disclosure will be described with reference to FIG. 25 to FIG. 27. In the following description, the same reference signs will be given to the configurations common to those already described, and duplicate description will be omitted. The treatment device 100D according to the present embodiment is different from the treatment device 100B of FIG. 18 to FIG. 20 in the point of further having a sheath 2.

[Treatment Device 100D]

FIG. 25 and FIG. 26 are plan views showing the treatment device 100D.

The treatment device 100D is formed in an elongated shape as a whole, and includes a gas pipeline 1D, the sheath 2, the electrode 3, and an operation portion 4D.

The gas pipeline (pipeline) 1D is a tubular member having an outer diameter that allows for the gas pipeline 1C to be inserted into the treatment device channel 230 and the sheath 2 of the endoscope 200. The tubular member is elongated and flexible. The internal space L1 of the gas pipeline 1D is a part of the gas flow path P1 through which the inert gas such as the argon gas flows. The gas pipeline 1D is made of a material having electrical insulation such as the PTFE.

The gas pipeline 1D has a proximal-end portion 11 and a distal-end portion 12B. The proximal-end portion 11 of the gas pipeline 1D is attached to the operation portion 4. Also, the gas pipeline 1D has a distal-end bending portion 15 and a flexible portion 19 between the distal-end portion 12B and the proximal-end portion 11. The gas pipeline 1D does not have the proximal-end bending portion 17. The distal-end bending portion 15 and the flexible portion 19 are connected in this sequence from the distal-end portion 12B toward the proximal-end portion 11.

The flexible portion 19 is a pipeline having no bending habit, and a proximal end thereof is attached to the operating portion 4D via the proximal-end portion 11.

The sheath 2 is a tubular member having an outer diameter that allows for the sheath 2 to be inserted into the treatment device channel 230 of the endoscope 200. The tubular member is elongated and flexible. The proximal-end portion 2 b of the sheath 2 is attached to the operation portion 4D. The sheath 2 has a sheath distal-end flexible portion 21, a sheath bending portion 22, and a sheath proximal-end flexible portion 23. The sheath distal-end flexible portion 21, the sheath bending portion 22, and the sheath proximal-end flexible portion 23 are connected in this sequence from the distal-end portion 2 a toward the proximal-end portion 2 b.

The sheath distal-end flexible portion 21 is a pipeline that does not have a bending habit.

The sheath bending portion 22 is a pipeline having a bending habit equivalent to that of the proximal-end bending portion 17 according to the embodiment of FIG. 1 to FIG. 16, and the sheath bending portion 22 is restored to a predetermined curved shape in a state where there is no external force applied. The shape of the sheath bending portion 22 shown in FIG. 25 is the predetermined bending shape in a state where there is no external force applied. The predetermined curved shape of the sheath bending portion 22 in a state where there is no external force applied is also referred to as an “initial bending shape”. The initial bending shape of the sheath bending portion 22 is curved along the virtual plane V.

The sheath proximal-end flexible portion 23 is a pipeline that does not have the bending habit, and is attached to the operation portion 4D via the proximal-end portion 2 b.

As shown in FIG. 25, when the distal-end bending portion 15 and the sheath bending portion 22 are in the initial bending shape, and the flexible portion 19, the sheath distal-end flexible portion 21 and the sheath proximal-end flexible portion 23 are in the linear state, the distal-end opening 14 c of the distal-end tip 14B provided in the distal-end portion 12B opens in a direction perpendicular to the virtual plane V.

FIG. 27 is a cross-sectional view showing the operation portion 4D.

The operation portion 4D includes an operation portion main body 40D to which the proximal-end portion 2 b of the sheath 2 is connected, a slider 41, and a gas-supply pipeline 42.

A distal-end portion of the operation unit body 40D is fixed to the proximal-end portion 2 b of the sheath 2. A slit 40 a extending in the axial direction A is formed in the operation portion main body 40D. The gas pipeline 1D and the gas-supply pipeline 42 are connected with each other, and the internal space L1 of the gas pipeline 1D communicates with the internal space L4 of the gas-supply pipeline 42.

The slider 41 is attached to the operation portion main body 40D, and the slider 41 is advanceable and retractable in the axial direction A along the slit 40 a. The slider 41 is attached to the proximal-end portion 11 of the gas pipeline 1D inside the operation portion main body 40D. By the surgeon advancing and retracting the slider 41 forward and backward with respect to the operation portion main body 40D, the surgeon can advance and retract the gas pipeline 1D with respect to the sheath 2 in the axial direction A.

Next, the effects of the treatment device 100D of the present embodiment will be described. The treatment device 100D, similar to the treatment device 100B according to the embodiment of FIG. 18 to FIG. 20, can be used in combination with the endoscope 200 for an endoscopic treatment method for the gastroesophageal reflux disease (GERD).

Similar to the embodiment of FIG. 18 to FIG. 20, the surgeon specifies the treatment region R (treatment area identification step). The surgeon makes the bending portion 204 to be in the up-angle state to observe and treat the gastroesophageal junction. The surgeon bulges the treatment region R by locally injecting the liquid into the submucosal layer N of the identified treatment region R (local injection step). Next, similar to the embodiment of FIG. 18 to FIG. 20, the surgeon performs the insertion step, the protrusion step, and the bending step.

When the sheath bending portion 22 passes through the treatment device channel 230 bent by the bending portion 204, the sheath bending portion 22 passively rotates around the central axis of the sheath 2 until the bending shape of the sheath bending portion 22 almost follows the bending shape of the treatment device channel 230.

When the sheath bending portion 22 passively rotates around the central axis of the sheath 2, the operation portion main body 40D rotates with the axial direction A as the rotation axis. The gas pipeline 1D fixed to the operation portion main body 40D rotates around the central axis of the gas pipeline 1D, and the distal-end opening 14 c moves with respect to the distal-end portion 201 of the endoscope 200. At that time, the distal-end opening 14 c faces a direction different from the protruding direction D of the distal-end tip 14B.

The distal-end bending portion 15 protrudes from the distal-end portion 230 a of the treatment device channel 230, and the distal-end bending portion 15 restores to the initial bending shape due to the bending habit. Therefore, similar to the embodiment of FIG. 18 to FIG. 20, it is easy for the surgeon to visually confirm the cauterization state of the treatment region R in the captured image at the time of cauterizing the treatment region R is cauterized.

As shown in FIG. 26, the surgeon retracts the gas pipeline 1D with respect to the sheath 2 in the axial direction A by retracting the slider 41 with respect to the operation portion main body 40D, and accommodates the distal-end bending portion 15 into the sheath 2. As a result, it is possible to change the direction in which the distal-end opening 14 c faces. If the distal-end opening 14 c is arranged at the position facing the protrusion direction D, it is easy for the surgeon to cauterize the treatment region R arranged in front of the distal-end tip 14A in the frontal approach AP1.

According to the treatment device 100D of the present embodiment, even in the case in which the gas pipeline 1D does not have the proximal-end bending portion 17, only if the sheath 2 in which the gas pipeline 1D is inserted has the sheath bending portion 22 with the bending habit, the same effects as that of the treatment device 100B according to the embodiment of FIG. 18 to FIG. 20 can be achieved.

Although the present embodiment of the present disclosure has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes and the like within a range that does not deviate from the scope of the present invention. In addition, the components shown in the above-described embodiments and the modifications example shown below can be appropriately combined and configured.

For example, in the above-described embodiment, the direction of the distal-end tip 14B can be changed by retracting the gas pipeline 1D with respect to the sheath 2 in the axial direction A and accommodating the distal-end bending portion 15 in the sheath 2. However, the method of changing the orientation of the distal-end tip 14B is not limited to this example. FIG. 28 is a view showing a distal-end portion of the treatment device 100E, which is a modification example of the treatment device 100. A wire 6 being advanceable and retractable from the operation portion 4 is attached to the distal-end tip 14B of the treatment device 110E. The surgeon can change the direction in which the distal-end opening 14 c faces by advancing and retracting the wire 6.

Although the respective embodiments and modifications of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and configurations in the respective embodiments and modifications within the scope not departing from the spirit of the present disclosure. It is possible to change the combination of elements, make various changes to each configuration element, or delete each configuration element. For example, the configuration according to any one of above-described embodiments and modifications of the present disclosure may be appropriately combined with each modification of the operation portion. The present disclosure is not limited by the above description, but only by the appended claims. 

What is claimed is:
 1. An endoscopic treatment device comprising: a pipeline having electrical insulation, the pipeline having an internal space through which inert gas can be passed; a distal-end tip attached to a distal end of the pipeline, the distal-end tip having an opening formed to communicate with the internal space such that the inert gas is disposable from the opening; and an electrode provided in the distal-end tip and configured to be energizable with a high-frequency current; wherein the pipeline includes: a proximal-end bending portion with a bending habit, and a distal-end flexible portion without a bending habit that is disposed distal to the proximal-end bending portion.
 2. The endoscopic treatment device according to claim 1, wherein: the proximal-end bending portion is bent along a virtual plane, and the opening is positioned on the virtual plane.
 3. The endoscopic treatment device according to claim 1, wherein the pipeline further includes a distal-end bending portion with a bending habit that is disposed distal to the distal-end flexible portion so that the distal-end flexible portion is disposed between the proximal-end bending portion and the distal-end bending portion.
 4. The endoscopic treatment device according to claim 3, wherein: the proximal-end bending portion is bent along a virtual plane, and the distal-end bending portion is bent in a direction intersecting with the virtual plane.
 5. The endoscopic treatment device according to claim 3, wherein: the proximal-end bending portion and the distal-end bending portion are bent along a virtual plane, and the opening is positioned on the virtual plane.
 6. The endoscopic treatment device according to claim 3, wherein a length of the proximal-end bending portion in an axial direction of the proximal-end bending portion is larger than a length of the distal-end flexible portion in an axial direction of the distal-end flexible portion.
 7. The endoscopic treatment device according to claim 1, wherein a length of the proximal-end bending portion in an axial direction of the proximal-end bending portion is larger than a length of the distal-end bending portion in the axial direction.
 8. The endoscopic treatment device according to claim 3, wherein a curvature of the distal-end bending portion is larger than a curvature of the proximal-end bending portion.
 9. The endoscopic treatment device according to claim 3, wherein a curvature radius of the distal-end bending portion is equal to or less than a length of the distal-end flexible portion in an axial direction of the distal-end flexible portion.
 10. An endoscopic treatment method using an endoscope in combination with a treatment device, the treatment device comprising: a pipeline having electrical insulation, the pipeline having an internal space through which inert gas can be passed; a distal-end tip attached to a distal end of the pipeline, the distal-end tip having an opening formed to communicate with the internal space such that the inert gas is disposable from the opening; and an electrode provided in the distal-end tip and configured to be energizable with a high-frequency current, the endoscopic treatment method comprising: inserting the treatment device through a channel of the endoscope; protruding a distal-end portion of the pipeline from a distal end of the channel and moving an opening of the distal-end tip from a protruding direction of the distal-end portion of the pipeline toward a direction different from the protruding direction; and in a state in which the opening of the distal-end tip is directed to the direction different from the protruding direction of the distal-end portion of the pipeline, injecting the inert gas into the internal space of the distal-end tip while energizing the electrode with the high-frequency current to cauterize a luminal wall of a hollow organ.
 11. The endoscopic treatment method according to claim 10, wherein the hollow organ is the upper gastrointestinal tract, the endoscopic treatment method further comprises: inserting the endoscope into the stomach; approaching the luminal wall in the vicinity of the cardia by bending a bending portion of the endoscope in the stomach; and directing the opening of the distal-end tip in a direction different from the protruding direction of the distal-end tip in a state in which the treatment device approaches the luminal wall in the vicinity of the cardia, and cauterizing the luminal wall of the hollow organ includes cauterizing the luminal wall in the vicinity of the cardia.
 12. The endoscopic treatment method according to claim 10, wherein: the pipeline includes a proximal-end bending portion with a bending habit configured to restore the proximal-end bending portion to a predetermined bending shape, when the proximal-end bending portion passes through the channel that is bent by the bending portion, the proximal-end bending portion passively rotates around a central axis of the pipeline until the bending shape of the proximal-end bending portion follows a bending shape of the channel, and when the proximal-end bending portion passively rotates around the central axis of the pipeline, the opening of the distal-end tip moves with respect to a distal-end portion of the endoscope. 